Dear Randy You added the following to ticket 102. It's a reasonable point, but I don't think it belongs in that ticket. I suggest we discuss it on the email list.
> On GOES-R ground, some of the data we report for a given geographic region > (i.e. a cell containing many observations) is the percent that a > particular geophysical quantity exists. > > We were planning on using the cell method "sum" because it generally > conforms to the definiiton of sum in Appendix E (The data values are > representative of a sum or accumulation over the cell. This is the default > method for a quantity that is extensive with respect to the specified > dimension.) > > The problem with doing this is ... > > Percent is not the same units of the geophysical quantity. To solve this, > the units column for the "sum" row in appendix E could be modified to > allow percent. > > Another option may be to treat "percent" as a cell method. I would say that the percent existence of X is a different geophysical quantity from X and therefore needs its own standard name, which will be dimensionless as you say (not in the units of X). This is like area_fraction quantities e.g. cloud_area_fraction or area_fraction_below_surface. Could you give some examples of X? The appropriate cell_method for the derived variable is "sum", as you suggest, since it represents the entire cell, not a point. Best wishes Jonathan _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
